WASHINGTON — Reeling from back-to-back presidential losses and struggling to cope with the country’s changing racial and ethnic makeup, the Republican National Committee plans to spend $10 million this year to send hundreds of party workers into Hispanic, African-American, and Asian communities to promote its brand among voters who overwhelmingly supported Democrats in 2012.

Committee chairman Reince Priebus on Sunday also proposed shortening the presidential nominating calendar in 2016 and limiting the number of primary-season debates to avoid the self-inflicted damage from inside-party squabbling on the eventual nominee. Priebus’s top-to-bottom changes include picking the moderators for the debates and then crowning the nominee as early as June so he or she could begin a general election campaign as quickly as possible.